A government security force member, in black clothes, beats a protester outside Freedom Park as other protesters run away in Phnom Penh, Cambodia, Thursday, May 1, 2014. Security forces have beaten demonstrators after a May day rally held in defiance of a government ban on public protests in the Cambodian capital. Nearly 1,000 factory workers and supporters of the opposition Cambodia National Rescue Party had gathered on the streets outside the city's Freedom Park, which had been barred to demonstrators and sealed off. (AP Photo) (The Associated Press)

A Buddhist monk takes a photo of riot police standing at Freedom Park in Phnom Penh, Cambodia, Thursday, May 1, 2014. Security forces have beaten demonstrators after a May day rally held in defiance of a government ban on public protests in the Cambodian capital. Nearly 1,000 factory workers and supporters of the opposition Cambodia National Rescue Party had gathered on the streets outside the city's Freedom Park, which had been barred to demonstrators and sealed off. (AP Photo) (The Associated Press)

Workers shout slogans as they hold a rally near the Presidential Palace to mark the Labor Day celebrations on Thursday, May 1, 2014 in Manila, Philippines. Various labor groups nationwide held protests, mostly to demand wage hikes, better working conditions and an end to corruption in the government. The sign reads: Workers Have Zero Benefits In The Four Years of Capitalist Government of Aquino. (AP Photo/Bullit Marquez) (The Associated Press)

A protester holds up a placard during a protest against the implementation of the Goods and Services Tax (GST) in Kuala Lumpur, Malaysia, Thursday, May 1, 2014. The placard reads: "Against GST." (AP Photo/Lai Seng Sin) (The Associated Press)

Protesters sit in front of the historical building of Sultan Abdul Samad during a protest against the implementation of the Goods and Services Tax (GST) in Kuala Lumpur, Malaysia, Thursday, May 1, 2014. (AP Photo/Lai Seng Sin) (The Associated Press)

PHNOM PENH, Cambodia – May Day demonstrators denounced low wages and called for reforms on Thursday during rallies that turned violent in Cambodia and in Turkey, where police cracked down on participants defying a ban on public protests.

Security forces in Istanbul's iconic Taksim Square pushed back demonstrators with water cannons and tear gas. Protesters retaliated by throwing objects at police.

In Phnom Pehn, witnesses said civilian auxiliary police, armed with clubs and often used by the government to break up protests, turned on the demonstrators after opposition leaders spoke to the crowd and left the rally site. The assaults appeared to be random and limited, and were over in less than an hour.

At least five people were hurt, said Om Sam Ath, an officer of the human rights group Licadho.

"These security forces seem to be addicted to beating people," he said. "Every time they disperse protesters, they beat people, and not one of them has been arrested."

Nearly 1,000 factory workers and supporters of the opposition Cambodia National Rescue Party gathered outside the city's Freedom Park, which had been sealed off with barbed wire with hundreds of police on guard. The event was held both to mark the labor holiday and kick off the opposition's campaign for local elections.

A ban on demonstrations has been in place since January, following numerous labor protests for a higher minimum wage and opposition demonstrations denouncing last July's general election as rigged.

Cambodia is formally democratic, but Prime Minister Hun Sen's authoritarian government has been in power for almost three decades while his opponents have complained of intimidation.

Opposition leader Sam Rainsy, speaking before the violence, condemned the government for banning workers from holding a May Day rally. He said he supports labor's demands for a higher minimum wage for garment factory workers. Textile exports are Cambodia's main foreign exchange earner.

In Moscow, about 100,000 people marched through Red Square, the first time the annual parade has been held on the vast cobblestoned square outside the Kremlin since the fall of the Soviet Union in 1991.

In keeping with Soviet-era traditions, Thursday's parade was organized by trade unions and honored the working man. But it also celebrated Russia's annexation of Crimea and was seen as part of President Vladimir Putin's efforts to stoke patriotic feelings.

Marchers held up signs saying "Let's go to Crimea for vacation" and "Putin is right." Russian flags fluttered through the crowd.

In the Philippines, thousands of workers marched peacefully in Manila to protest low wages and employers' practice of replacing regular employees with temporary hires who get low pay and little or no benefits. They also decried what they said was the failure of President Benigno Aquino III to deliver on his anti-corruption and pro-poor reforms.

The Philippine economy grew 7.2 percent last year despite a string of natural calamities. Still, data show 24.9 percent of Filipinos were considered poor in the first semester of 2013, down from 27.9 percent in the same period in 2012.

"Raise wages, bring down prices!" members of labor groups chanted as they marched under the sweltering sun toward a historic bridge near the presidential palace, carrying colorful steamers. One of the banners said: "It is not moral, it is not right, it is unjust if progress is only for a few!"

"There is growth in this country but none of the working class has actually benefited from this growth," said Joshua Mata, one of the rally leaders.

Thousands of Malaysians held a peaceful protest in downtown Kuala Lumpur against a looming goods and services tax that they fear will increase the cost of living.

The government has said a 6 percent tax will be implemented from April next year to boost revenue and curb rising debt. There are however, mounting public concerns that prices of goods will soar and further burden the poor after the government last year cut subsidies on fuel and electricity.

Opposition leader Anwar Ibrahim, who heads a three-member alliance, said that the rally was a clear message that the people are against the new tax, "which is only going to make the cronies richer."

Iranian President Hassan Rouhani told thousands of laborers gathered to celebrate International Workers' Day in the capital, Tehran, that he supports the establishment of unions "free of any interference by the state."

Rouhani's predecessor, Ahmadinejad, had dissolved many unions, leaving only a few perfunctory and powerless organizations.

"Workers' organizations and unions should be formed freely," Rouhani said. "The government should not interfere in these associations."

Dozens of people, mostly members of the Iraqi Communist Party, held a rally near the party headquarters in downtown Baghdad, raising Iraqi flags and those of the former Soviet Union.